parallelism_with_yield.py

"""
Demonstration how to execute Python code parallel with `yield` keyword.

Need Python 3.3 or above to use "return" in generator function.

This experiment is a step to implement Node.JS-like parallelism into Python web framework WebPages <https://github.com/webpages/webpages>
"""

def query_db():
    return "result from database"

def operation_with_file(filename):
    return "file content"

def render(template, data):
    return template.format(data)

def request_handler():
    filename = "hello.html"
    template = yield operation_with_file(filename)
    data = yield query_db()
    return render(template, data)

for result in request_handler():
    pass

Seems 11 years ago I thought about async abilities in Python :-)